Rindskopf Striated production variation, or "Mom always liked you best!"

I was excited about getting the piece on the left today to go with a piece I already had in my collection (the one on the right), thinking I would have a pair, which would be cool, right?

I was surprised at the stark difference between the two pieces - the new piece hardly has any iridescence - the one I already had we highly iridescent. Furthermore, shining light through the pontil reveals what appears to be different colored grounds? I'm not sure if it's that, or just the difference between the amount of sprayed on iridescence. At any rate, now I have two, but one of them is clearly the favored son.

Amusing sideline - the striated piece on the left in these photos was part of an eBay auction for two blown glass vases, brand new without original packaging. A strange description indeed, because the other piece was quite obviously a piece of Brush McCoy type pottery!